Palo Alto (CA) Temperature by Month
Palo Alto in California, United States of America sees significant seasonal temperature differences, with daytime highs between 15°C (59°F) in December and 26°C (79°F) in September, averaging 21°C (70°F) annually. Explore the full monthly breakdown below.
Palo Alto Monthly Temperatures
In Palo Alto, temperatures can shift dramatically between warm in summer and mild in winter. Nights follow the same pattern, with lows ranging from 13°C (55°F) in September to 5°C (41°F) in December.
The chart below illustrates the average maximum day and minimum night temperatures in Palo Alto by month:
From around 4 AM to 6 AM temperatures are at their lowest; by 3 PM they've climbed to their daily peak. September, the warmest month, averages 270 hours of sunshine.
The chart below shows the average temperature throughout the year:
Temperature: Palo Alto vs the United States of America
The map below shows the annual temperature across the United States of America. You can also select individual months if you want to compare a specific time of year.
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Palo Alto vs World: Temperature Compared
Palo Alto's average annual maximum temperature is 21°C (70°F). To put that in context, here's how it compares to a few well-known destinations:
Seville, Spain averages 23°C (73°F) a year — one of the warmer cities in Western Europe, with long hot summers.
Toronto, Canada averages 13°C (55°F) annually, with cold snowy winters balanced by genuinely warm summers.
Seoul, South Korea averages 18°C (64°F) a year, with four clear seasons, cold winters, and hot humid summers.
Brisbane, Australia averages 26°C (79°F) a year, with warm winters and hot, humid summers.
What Does the Temperature Feel Like in Palo Alto?
Temperature alone doesn't tell the whole story — humidity plays a big role in how warm or cold it actually feels. High humidity in summer makes the heat feel more intense, particularly once temperatures climb above 25°C. In winter, the same humidity can make cold air feel sharper than the thermometer suggests.
In Palo Alto, December is the coolest month, with average highs of 15°C (59°F) and humidity around 78% — considered high. In September, the warmest month, temperatures average 26°C (79°F) with 73% humidity — conditions that feel high. For a full picture, see our humidity page.
Climate temperature data is typically calculated as a 30-year average. This smooths out year-to-year variability and gives a more reliable picture of what a place is actually like, rather than what happened in any single unusual year.
The readings come from a range of sources — land-based weather stations, ocean buoys, ships, and satellites. That data is collected by weather services around the world, then pooled, quality-checked, and averaged to produce the climate records you see here.
For cities and regions with significant elevation, altitude is one of the biggest factors shaping local temperatures. As a rule of thumb, temperatures fall by around 6°C for every 1,000 metres gained — so a city at 2,000 metres will typically be around 12°C cooler than a city at sea level in the same region. Higher ground also tends to see more dramatic day-to-night temperature swings, since thinner air loses heat faster after sunset.
For more on Palo Alto's weather — including monthly rainfall, sunshine hours, and humidity — visit our Palo Alto climate page.
